Characterization of polythiiranes using multidetection size exclusion chromatography

Series of polythiiranes with pendant Oxyethylene groups have been characterised. Size Exclusion Chromatography (S.E.C.) analysis of polymers with such polar groups needs some precautions. Accurate measurement of dn/dc is used in order to check the amount of recovery of the injected samples. Polymers with short side chains are normally eluted, but an irreversible adsorption occurs for long side chains. There appears to be an intermediate situation for which adsorption is reversible and produces an important dependence of elution volume on injected concentration. Using a combined Light Scattering, a Viscometric detector, and additional off-line Dynamic Light Scattering (D.L.S.) measurements, it was possible to study, more completely, the relationship between size and molecular weight for such polymers. When some of these polymers do not exhibit any adsorption phenomenon, universal calibration is observed and a constant correction factor is available, allowing the conversion of relative molecular weights into absolute molecular weights.